Bill Fefferman is an assistant research professor in the Joint Center for Quantum Information and Computer Science (QuICS) and a research scientist at the National Institute of Standards and Technology (NIST).

His work focuses on quantum computation and computational complexity theory, with an emphasis on understanding the capabilities of near term quantum devices and experiments.

Fefferman previously held postdoctoral positions at UC Berkeley and at the University of Maryland in QuICS.

He received his doctorate in computer science from Caltech in 2014.

In 2017 Fefferman was the recipient of a Young Investigator Award from the Air Force Office of Scientific Research to help support his research on the power of near-term quantum systems.